Drill bits used to drill wellbores through geological formations generally fall within one of two broad categories of bit structures: “roller cone” bits and “fixed cutter” or “drag” drill bits. Roller cone bits include one or more roller cones rotationally mounted to the bit body. During operation, the roller cones will rotate with respect to the drillstring to drill a wellbore in a geological formation. A drag drill bit has a body formed from steel or another high strength material, and cutting elements (sometimes referred to as cutter elements, cutters, or inserts) attached at selected positions to the bit body. The cutting elements are located on a plurality of blades. Unlike the cones of the roller cone bit, the blades of the drag bit are stationary with respect to the drill string. The drag drill bit relies on rotation of the drillstring to cut through a geological formation.
As the blades of the drag bit are stationary with respect to the drill string, the same cutting elements are exposed to the geological formation during drilling. The cutting elements may include diamond impregnated in the blade or bit (on the bits known as diamond impregnated bits) or may be formed having a cylindrical substrate or support stud made of carbide, for example, tungsten carbide, and an ultra-hard cutting surface layer made of polycrystalline diamond material or a polycrystalline boron nitride material deposited or otherwise bonded to the substrate (on bits referred to as PDC bits).